Systemd returns 0 for services that don't run.
It wasn't checked well causing weird effect:
trying to terminate an application not running
killed afm-system-daemon because kill(0) kills
all processes of the group of the caller.
Bug-AGL: SPEC-1836
Change-Id: I1bd64faf871ecd42aaaa5449312e8b8cb26ee9dd
Signed-off-by: José Bollo <jose.bollo@iot.bzh>